#include <stddef.h>
#include <stdio.h>

size_t strlen(const char *str)
{
	if (str == NULL)
		return 0;

	size_t counter = 0;
	while (*str++)
		++counter;
	return counter;
}

int main()
{
	printf("%u\n", strlen("Eterfree"));
	return 0;
}
